Greetings All.
Been a while. Now retired and got time to get Cooper up and runing.
At the last Bay 2 Birdwood run, the generator started screaming. Nursed it home and found the brass bush ablitorated. New bush found and fitted at local auto elec. He said everything else looks ok. I fitted generator and charge light stays on. Took it off and double checked brush wires etc for faults. All seem good.
Looked on YouTube and saw how to test generator. Put in vice, joined two spade connections and gave it 12volts. It span the generator like an elec motor.
Am I right thinking the generator (when flopping around) damaged the regulator? Is this likely.
Any helpful hints would help while I recharge the battery.
Alex.

Possible...did you check the brushes as well?

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"Show me the Mini!"

Alex
If the generator spins when connected as a motor then it (and the brushes) are probably good. The auto elec would (should?) have checked them.
The generator does not have a "regulator". The "regulator" circuits are in the plastic control box usually forward of the fuse box.
I wasted many, many hours trying to fix charging rates and voltages before I discovered how brilliant this little box is. It does about ten different things, all at once, including supplying a voltage to the ignition/charging light.
If the output of the generator at D is several volts below the battery voltage at A1 (say at idle) then the light comes on, BUT it can also come on if the voltage is several volts above A1.
Go through EVERY step in ORDER in your Manual to test the generator and control box. As you follow each step you test and set the voltages and currents going to and from the generator, clean up and test the connectors, and set the charging voltages and currents to and from the battery depending on its charge.
Don't be a mug like me and try to skip steps because you know better than the Prince of Darkness.

P.S. Use an analogue voltmeter for testing as the voltages are changing up to 50 times a second. The analogue meter responds slowly and will show the "average" CORRECT voltage, but a digital meter will "sample" voltages too fast, and will show 0 volts or 15 volts or anywhere between.
BMC should have mentioned this in the instructions??????
Good Luck.

9YaTaH and Dave.

Thanks for the info. Will sit down and work this out. Battery should be charged soon.
Much appretiated
Alex.

9YaTaH _ couldn't see your name anywhere.

There are some reproductions of Lucas literature available here, outlining tests of generators and regulators, if you care to get technical:
http://mk1-performance-conversions.co.u ... trical.htm

Failing this, look for an old auto-electrician!

Thanks Bill.
Just put it back together and did a good long test run.
Charge light still on. Gonna pop over to a mates place to try and see what it is or isn't doing.
I changed the regulator for a good spare I had. So I believe it may all be down to the light itself. (I may be dreaming)
Alex.
Will check out the info, thanks. I've only got a digital multimetre and I'm no expert. Ha!

You didn’t replace the bulb with an led?

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when you connected the battery up to it did you connect it in the same polarity to earth as your car is ?
If you did it wrong you would have reversed the polarity and it wont charge on the car

Thanks all.
Can't sort this issue.might be time for auto electrician. Mechanic mate tried several checks. I've put another generator on, another regulator on, checked all the connections, even compared it to my 850.
Read through the wiring diagrams too. Polarity should be ok, however the radio doesn't power up?
It drives really good. Is there a simple check to clarify polarity?
Just checked thermo fan, that spins in right direction.
Very peed off at moment. Wife says sell, I say fix!
Alex.

Alex
Tell your wife that she is right about selling the car but that it is important for your Covid psychological survival plan to battle through till you have fixed the car.
Bill B's attachment has the Lucas Generator and Control Box Tests to find the problem.
Guna mk1 could be on the money if your car is positive earth and/or you connected the battery the wrong way around to run the generator as a motor.
The generator is meant to have a slight residual magnetic field in the steel case. When the generator first spins at start up this residual magnetic field helps to generate 2 - 4 volts in the armature. The control box directs this back to the field windings and the voltage increases until the control box switches into full on mode. The control box "tries" to keep the generator about 2 - 3 volts above the battery voltage.
If guna mk1 is right, you might have reversed the residual magnetic field and so the start up voltage will be wrong and Generator Test 1 will show this even with a digital multimeter.
Cooper cars were all positive earth. (I think?). Has it been changed to negative? If you got the battery the wrong way around after charging it could have fried the radio and remagnetised the generator?
Keep going one Test at a time. Good Luck. Dave D

Have you checked the fuses? The generator may have shorted internal when the bush collapsed blowing a fuse?

I had the same problem on my early S with generator. Tried everything including new regulator.Finally cleaned all old regulator points with rough abrasive paper as seen on Youtube - light went out and battery gets charged. Definitely fixed it as the light sometimes comes on when at a very slow idle.

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Cooper S Mk2
Cooper S Mk1
ex Cooper S Mk2, various Morris 1100s, 1300s, 1500s, Leyland Sherpa!

Thanks all.
Tried everything. Many times.
Followed test manual. Several times.
Took generator and regulator to local auto electrician. Old fella said he knows them back to front.
Waiting for diagnosis call.
Alex.

Good Luck.
Let us know what he decides. It might help us avoid the dreaded "Sell it" conversation.
Dave D

Time to fit an Alternator (I'm thinking)

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"Show me the Mini!"